Bridge to clean energy: Leaders mull WNC’s energy future

When the first transmission lines began popping up in the mountains 100 years ago, only one type of power provided the energy traveling through them — hydroelectric.

“What made Western North Carolina so attractive for developing hydro assets is that if we were to lop off the Pacific Northwest, here in Western North Carolina we receive some of the highest rainfall totals in the continental United States,” said Lisa Leatherman, local government and community relations manager for Duke Energy.

Abundant rainfall combined with the mountains’ topography made hydro a reliable source of renewable energy. After building a dam to block the river’s flow, water is released at a controlled rate to turn the turbines, which in turn power electrical generators. As long as there’s water in the lake, the plant can keep generating energy.

The region’s first dams were mostly small structures that generated just enough to supply the minimal needs of tiny towns like Andrews and Bryson City during the 1920s and 1930s. But then World War II started, and power generation became a matter of national defense. Thorpe Dam, which holds back Lake Glenville, began operating in 1941, and even today it has the largest head — the height difference between where the water enters and where it leaves — of any dam east of the Rockies. Head translates to generation capacity: during the war, Thorpe produced enough power for Alcoa to make aluminum for two B-25 bombers each day.

Until the mid-1970s, hydroelectric facilities in Western North Carolina produced enough power to satisfy the region’s entire electrical demand, Leatherman said — but that’s no longer the case. Due partly to higher per capita and overall energy requirements and partly to limits on how far Duke can draw down the reservoir levels, hydroelectricity now makes up only a small percentage of the region’s total energy supply.

Defining ‘clean’

With coal-polluted skies still a recent memory and the warming climate a present crisis, everyone from government officials to power companies to individual community members is scrambling to answer a pivotal question — what is the best way to power WNC into the future?

“Sustainability is on a continuum, and in some ways there’s no absolute sustainability,” said Sam Ruark, executive director of Green Built Alliance.

The term “clean energy” means different things to different people. Hydroelectric generation, for instance, is renewable and carbon-free — but most environmental agencies and organizations don’t count it as clean . Generating hydroelectric energy requires constructing a dam to block up a free-flowing stream, which completely changes the nature of the upstream aquatic community and divides the river into two unconnected segments. Evaporation and micro-organism growth in the upstream reservoir can also contribute to climate change. These days, dam demolition is more common in the United States than dam construction.

Wood is another renewable resource that Western North Carolina has in abundance.

Blair Bishop, a professional forester in Waynesville who sits on the executive committee of the N.C. Forestry Association , thinks it should be counted as clean. It’s local and renewable, and timberlands tend to be easier on the eyes than fields full of solar panels or wind turbines.

“Our forests here naturally regenerate (in general), so at a large scale you have a product that quickly after harvest is already establishing a new stand of vigorously growing trees that take in a lot of carbon in their initial stages of growth,” he said.

Not everyone shares that view, however. While new trees growing in place of harvested ones do rapidly sequester carbon, when burned wood energy releases carbon at a rate on par with coal. The N.C. Clean Energy Plan points out that wood pellets produced in North Carolina are exported rather than consumed locally, mostly to Europe.

“There are currently no known plans for the industry to become a contributor to N.C.’s energy sector in the coming years,” the plan reads. “If this trend reverses, N.C. should not support activities that would increase emissions from its electricity generation sector.”

Half of the power Duke Energy’s North Carolina customers use comes from another renewable, carbon-free source many people don’t think of as “clean” — nuclear energy . Located on Lake Keowee in South Carolina, Oconee Nuclear Station , Duke’s closest nuclear plant, has produced more than 500 million megawatt hours of electricity since opening in 1973 and is one of the country’s largest nuclear plants, generating enough electricity to power 1.9 million homes.

Nuclear facilities produce a small amount of hazardous waste and require strict security measures to operate safely. But the power produced is reliable and emission-free, said Duke’s communication officer Bill Norton, adding that the company’s nuclear plants have been “operating safely and reliably for decades.” Nuclear energy will loom large in the proposed plan to achieve carbon neutrality by 2050 that Duke plans to release May 16, Norton said.

In addition to continuing operations at its Lake Keowee plant, Duke might also take advantage of a new technology — small modular nuclear reactors that have lesser footprints and construction costs than traditional nuclear facilities and can be built in locations not suitable for larger plants.

“It’s the backbone of our system in the Carolinas,” Norton said of nuclear power. “It’s dependable and it’s carbon-free. That backbone is what is going to enable us to grow other resources.”

Growing solar

Those “other resources” include two of the most discussed renewable energy sources — wind and solar. Duke’s forthcoming plan will feature “exponential growth” in these areas, Norton said.

However, it’s doubtful that much of that generation will occur in Western North Carolina. Wind energy is likely to come mainly from coastal and offshore wind farms, because any productive wind turbine installed in the western part of the state would have to go on a ridgetop. From aesthetic viewshed issues to the logistical and environmental challenges that would go along with cutting roads to deliver gargantuan turbine components to remote ridges — a typical model weighs 164 tons — and digging holes in rocky ground sufficient to anchor them, there are many reasons why large-scale wind energy production is unlikely to happen in Western North Carolina.

Solar panels are a much more common sight, and indeed North Carolina is consistently ranked as one of the country’s top solar-producing states. However, the lion’s share of that production occurs further east.

“Any flat land in the mountains generally has a higher value for businesses, homes, what industry may be interested in coming here,” Leatherman said. “I think our geography that makes it very interesting and accommodating for hydro makes it less accommodating for other potential energy sources.”

Ruark allows that utility-scale solar isn’t likely to overtake Western North Carolina, but through Greenbuilt Alliance and the Blue Horizons Project , he’s working to help individual homes and businesses install rooftop solar arrays that will produce renewable energy for their own power needs and reduce their reliance on the grid.

“There’s still many roofs to cover, both residents and commercial businesses, and the price of solar keeps getting better and better,” he said, “although there are some supply issues at this point.”

Energy storage is also a challenge when it comes to solar. Peak solar production occurs during the afternoon of a sunny summer day, and that doesn’t coincide with peak energy demand, requiring a method of storing energy until customers need it. The lithium battery is the most common method of solar energy storage, but it has its own issues. The batteries have a limited lifespan, are challenging to recycle and require mining of rare earth metals to construct.

In its forthcoming energy plan, Duke will outline a plan to use its dam at Bad Creek in South Carolina as a de facto battery to expand solar utilities, Norton said.

“When you have that excess solar power or we have excess nuclear power, we use it to pump the water in Bad Creek uphill,” he said. “When the power is needed, it flows through turbines downhill, generating electricity.”

The dam can currently store up to 1,400 megawatts, and an ongoing feasibility study is evaluating a plan to expand that capacity by adding a second powerhouse.

“We’re going to grow solar significantly, and it will start storing more of that surplus energy,” Norton said.

Tackling efficiency

Unlike North Carolinians of 100 years ago, today’s residents don’t rely solely on power produced in their own backyard.

Duke Energy operates a massive grid that its customers can draw on collectively, and Duke’s grid is tied into those of other power companies so that, should its capacity come up short for some reason, it could buy electricity from another company to prevent customers from sitting in the dark. Duke customers in North Carolina rely on an energy supply composed of about 50% nuclear, 25% natural gas, 16% coal, 6% solar and 3% hydro.

But for Western North Carolina specifically, there’s an upper limit to how much power the region could generate for itself through favored renewables like solar. Ruark estimates that if every building in the region with quality sun exposure installed rooftop solar panels, the region would still be able to meet only about one-fifth of its total energy demand.

“People get really excited about renewable energy,” said Lauren Bishop, chief sustainability officer at Western Carolina University. “It’s cool. The technology is cool. But they tend to forget about energy efficiency.”

According to the U.S. Energy Information Administration , in 2020, 20% of carbon dioxide emissions came from residential buildings — less than the 36% that came from transportation or 29% that came from industry, but still significant.

“When someone comes to me and asks me, ‘Hey, I want to put solar panels on my house. How do I go about doing that?’ I always tell them that the first thing you need to do is get an energy audit and make sure your house is as energy efficient as possible,” Bishop said.

Not only will a more efficient house cost its owner less in monthly utility bills, but it will also more accurately signal to the utility provider how much power the community needs — important information when that company is making decisions about how much energy it must produce to meet customer demand. In Bishop’s view, energy conservation is the “the best bang for your buck” when it comes to supporting the clean energy transition.

Efficiency upgrades are especially important in the mountain region, which is rife with old, inefficient houses, Ruark said.

“Taking the existing housing stock that’s old, and retrofitting the home with energy efficiency, you actually get a lot more savings than you do if you’re trying to retrofit a newer home, because the older home was so much more inefficient,” he said.

Since the 2002 passage of North Carolina’s Clean Smokestacks Act, the state has been on an upward trajectory toward cleaner air and cleaner energy — a trajectory accelerated by a bipartisan bill enacted in October 2021 that commits the state to achieving carbon neutrality by 2050 (see Energy Legislation, page 7).

In 2005, coal supplied about half of North Carolina’s power — now Duke is targeting it to provide less than 5% of total generation by 2030 and 0% by 2035, Norton said. According to the North Carolina Clean Energy Plan, monthly nationwide electric generation from renewable sources exceeded coal-fired generation for the first time in April 2019, with renewables supplying 23% of the total that month compared to coal’s 20%. Today, most new generating capacity is renewable-driven.

Every energy source has an impact, and every generation technique comes with constraints. But the situation is not static, morphing each day as attitudes shift, laws change and inventors work to overcome today’s constraints.

“We’re in this movement, building the bridge to the future we envision,” said Ruark, “and we’re still in that bridge, and we still haven’t come to the other side.”

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